The invention relates to a corner fastener for the inside end of the runner rail of drawer guides in which the guide rail to be fastened to the cabinet wall is engaged in the corresponding runner rail consisting of an inverted channel removably fastened to the bottom of the drawer and having on its interior tracks for rolling bodies which are held in an elongated cage and can roll on tracks formed by associated areas of the inside surface of the runner rail on the one side and, on the other side, on tracks formed by associated portions of the inside surface of the runner rail, thus permitting a longitudinal movement of the runner rail relative to the guide rail, a front-end corner fastener which can be fastened under the bottom of the drawer being associated with the front end of the runner rail and in which the front end of the runner rail is held, and the corner fastener that is to be fastened in the back corner of the drawer has two clips projecting downward below the drawer bottom, of which at least one clips onto the runner rail, the two clips being integral with a corner fastener which can be fastened in the back corner of a corresponding drawer and joins together the inside end of a drawer side and the associated end of the drawer back.
Drawer guides of the kind here in question have, on account of the great number of rolling bodies in the form of balls and/or rollers offset not only in the direction of drawer movement but also at right angles thereto, have in addition to easy running and great load bearing capacity the additional advantage that even in the fully extended state they have a high transverse stability, so that a drawer mounted thereby on a cabinet has no marked free transverse play even in the fully extended state. Consequently drawer guides of this kind are being used increasingly for mounting drawers in high-quality furniture. In comparison to rolling drawer guides which are likewise widely used but are more critical in the fully extended state, the drawer guides with rolling bodies of the kind here in question are more complex and accordingly expensive to manufacture. To be able to offer them on a price-competitive basis they have to be manufactured in larger series. This means, however, that only certain frequently used lengths of these drawer guides are available, while for drawers of the kind here in question with a depth different from the standard dimensions are not offered in precisely fitting lengths. The plastic cage holding the roller bodies between the guide rail and the runner rail and fixing them at their mutual distance apart requires that the length of movement of the drawer guides here in question is limited to a length that is shorter than the length of the corresponding drawer, so that the back of the fully extended drawer still remains inside of the corresponding cabinet by the length of the cage. That is to say, drawer guides of the kind here in question are so-called " part-length guides." Especially in the case of shallow drawers of very great length, the rear part of the drawer that in the extended state is still within the cabinet is harder to see and reach. It would therefore be desirable to make the drawer guides as so-called "full-length guides" in which the corresponding drawer can be drawn so far out of the cabinet that its back wall will be approximately flush with the front of the cabinet. In the case of drawer guides of another kind, as for example the above-mentioned roller guides, full-length guides are obtained by combining two single guides into so-called "double guides." This recourse, however, is impossible in the case of the drawer guides of the kind here in question for reasons of price. On the other hand, however, in a number of cases, especially in cabinets of great depth, such as kitchen floor cabinets, drawers of less depth than the cabinet are manufactured, and then frequently no drawer guide of the kind here in question is obtainable in the required length, while a longer drawer guide would be available to fit the cabinet. The use of a longer drawer guide would then have even the advantage that an additional extended length is won, i.e., the drawer can be pulled all the way out of the cabinet the same as one with a full-length guide. The runner rail of a lengthened drawer guide then, of course, projects behind the back of the drawer, in which case the problem arises of how to attach this projecting end to the drawer, inasmuch as the runner rail must be removable and must be able to be fastened quickly, easily and removably on the drawer. To fasten the front end of the runner rail at the drawer front, mounting hardware is available (DE-OS 36 32 442). For mounting the projecting rear ends of runner rails, systems have been developed in special cases, but they are limited to those runner rails whose inside end is fastened to the drawer in a particular manner. These are runner rails in which a tongue is stamped from the web of the runner rail and then bent to form a mounting hook by first bending the tongue at right angles out of the web and then bending a portion of it forward at right angles, i.e., to a position parallel to the web. When it is installed on a drawer this hook section parallel to the web is inserted into a corresponding bore in the back of the drawer. In the case of an extended runner rail reaching past the back of the drawer, such a method of fastening is obviously impossible, and therefore in the case of the older solution (DE-OS 36 41 325) a corner fastener is placed on the projecting end of the runner rail and from its front end facing the drawer back a bolt protrudes which can be inserted into the bore serving to accommodate the horizontal section of the above-mentioned hook in the runner rail. In the rear end of the corner fastener, a bore is then again provided, into which the hook formed on the runner rail can be inserted. It is obvious that these corner fasteners must correspond exactly in length to the amount by which the runner rail projects past the drawer back. Since this length is not established, but depends on the length of the drawer, the corner fasteners must be made of a length corresponding in each case to the special application, or cut afterward to the desired length. The applicant has therefore developed mounting hardware of the kind described above, in a proposal not previously disclosed (German Patent Application P 40 12 650.1), in which the runner rail is held on the drawer back by clips by which during assembly it can be pushed through from the drawer back until the front end of the runner rail is held in the associated mounting hardware. The length by which the rear end of the runner rail protrudes is of no importance. Especially in the case of drawers with chambered sides of extruded aluminum, this mounting hardware can be further developed such that it is usable simultaneously also as hardware for joining the drawer side and drawer back by inserting the provided mounting piece on the one hand from the back end into the chamber in the drawer wall extrusion and on the other hand joining it to the end surface of the drawer back which is either also made of a metal extrusion or it is made from wood material.
The invention, on the other hand, is addressed to the problem of devising a corner fastener of this kind which will serve simultaneously as a device for joining the side and back of a drawer and for mounting the rear end of the runner rail of the drawer guides here in question, and which will also be usable on drawers in which both the sides and the back are made of wooden materials.